WASHINGTON (CNN) -- A helicopter carrying three U.S. senators was forced to make an emergency landing in Afghanistan Thursday, military and congressional sources tell CNN.

The military helicopter carrying Democratic Sens. Joseph Biden of Delaware and John Kerry of Massachusetts, and Republican Sen. Chuck Hagel of Nebraska had to land in the mountains because of a snowstorm, said Elizabeth Alexander, a spokeswoman for Biden.

No one was hurt in the incident, said Kerry spokesman David Wade. The senators proceeded to their destination in a ground convoy after the helicopter landed in a field, he said.

"After several hours, the senators were evacuated by American troops and returned overland to Bagram Air base, and left for their next scheduled stop in Ankara, Turkey," Wade added.

Pentagon officials said the incident occurred at approximately 8:30 a.m. ET.

Sen. Biden is the chairman of the Senate Foreign Relations Committee. Sens. Kerry and Hagel are members of the committee. Their aides were also on the helicopter.E-mail to a friend